python3.9 changed/fixed codec.register behavior to always replace
hyphen with underscore for passed in codec names:
https://bugs.python.org/issue37751
So the custom Ucs2Search needs to be adapted to handle 'ucs_2' in
addition to existing 'ucs-2' for back compat.
This fixes test failures on python3.9, example:
======================================================================
FAIL: testUtf16InUniFile (CheckUnicodeSourceFiles.Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 375, in PreProcess
FileIn = UniFileClassObject.OpenUniFile(LongFilePath(File.Path))
File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 303, in OpenUniFile
UniFileClassObject.VerifyUcs2Data(FileIn, FileName, Encoding)
File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 312, in VerifyUcs2Data
Ucs2Info = codecs.lookup('ucs-2')
LookupError: unknown encoding: ucs-2
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>